#!/bin/sh
#
# Copyright (c) 2014 David Vossel <davidvossel@gmail.com>
#                    All Rights Reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of version 2 of the GNU General Public License as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it would be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
#
# Further, this software is distributed without any warranty that it is
# free of the rightful claim of any third person regarding infringement
# or the like.  Any license provided herein, whether implied or
# otherwise, applies only to this software file.  Patent licenses, if
# any, provided herein do not apply to combinations of this program with
# other software, or any other product whatsoever.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write the Free Software Foundation,
# Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
#

#######################################################################
# Initialization:

: ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/lib/heartbeat}
. ${OCF_FUNCTIONS_DIR}/ocf-shellfuncs

# Parameter defaults

OCF_RESKEY_set_policy_default=""

: ${OCF_RESKEY_set_policy=${OCF_RESKEY_set_policy_default}}

#######################################################################

# This arbitrary value here is used by the rmq_start action to
# signify that the resource agent must retry the start process
# It might potentially conflict with OCF assigned error code
# in the future.
RMQ_TRY_RESTART_ERROR_CODE=126

RMQ_SERVER=/usr/sbin/rabbitmq-server
RMQ_CTL=/usr/sbin/rabbitmqctl
RMQ_EVAL="${RMQ_CTL} eval -q"
RMQ_DATA_DIR="/var/lib/rabbitmq/mnesia"
RMQ_PID_DIR="/var/run/rabbitmq"
RMQ_PID_FILE="/var/run/rabbitmq/rmq.pid"
RMQ_LOG_DIR="/var/log/rabbitmq"
if [ "$__OCF_ACTION" != "meta-data" ]; then
	NODENAME=$(ocf_attribute_target)
fi

# this attr represents the current active local rmq node name.
# when rmq stops or the node is fenced, this attr disappears
RMQ_CRM_ATTR_COOKIE="rmq-node-attr-${OCF_RESOURCE_INSTANCE}"
# this attr represents the last known active local rmq node name
# when rmp stops or the node is fenced, the attr stays forever so
# we can continue to map an offline pcmk node to it's rmq node name
# equivalent. 
RMQ_CRM_ATTR_COOKIE_LAST_KNOWN="rmq-node-attr-last-known-${OCF_RESOURCE_INSTANCE}"

meta_data() {
	cat <<END
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="rabbitmq-cluster">
<version>1.0</version>

<longdesc lang="en">
Starts cloned rabbitmq cluster instance. NB: note that this RA
cannot be spawned across a mix of pacemaker and pacemaker-remote nodes.
Only on pacemaker *or* pacemaker-remote nodes exclusively.
</longdesc>
<shortdesc lang="en">rabbitmq clustered</shortdesc>

<parameters>
<parameter name="set_policy" unique="1">
<longdesc lang="en">
Policy string to pass to 'rabbitmqctl set_policy' right after bootstrapping the first rabbitmq instance.
</longdesc>
<shortdesc lang="en">rabbitmqctl set_policy args</shortdesc>
<content type="string" default="${OCF_RESKEY_set_policy_default}" />
</parameter>

</parameters>

<actions>
<action name="start"        timeout="100s" />
<action name="stop"         timeout="90s" />
<action name="monitor"      timeout="40s" interval="10s" depth="0" />
<action name="meta-data"    timeout="10s" />
<action name="validate-all"   timeout="20s" />
</actions>
</resource-agent>
END
}

#######################################################################

rmq_usage() {
	cat <<END
usage: $0 {start|stop|monitor|notify|validate-all|meta-data}

Expects to have a fully populated OCF RA-compliant environment set.
END
}

rmq_wipe_data()
{
	rm -rf $RMQ_DATA_DIR > /dev/null 2>&1 
}

rmq_local_node()
{

	local node_name=$($RMQ_CTL status 2>&1 | sed -n -e "s/^.*[S|s]tatus of node \(.*\)\s.*$/\1/p" | tr -d "'")

	if [ -z "$node_name" ]; then
		node_name=$(cat /etc/rabbitmq/rabbitmq-env.conf 2>/dev/null | grep "\s*RABBITMQ_NODENAME=" | awk -F= '{print $2}')
	fi

	echo "$node_name"
}

rmq_join_list()
{
	local join_list=$(cibadmin -Q --xpath "//node_state[@crmd='online']//nvpair[@name='$RMQ_CRM_ATTR_COOKIE']" | grep "$RMQ_CRM_ATTR_COOKIE" | sed -n -e "s/^.*value=.\(.*\)\".*$/\1/p")
	# If join_list is empty we want to check if there are any remote nodes
	# where rabbitmq is allowed to run (i.e. nodes without the crmd=online selector)
	if [ -z "$join_list" ]; then
		# Get all the nodes written in the ATTR_COOKIE no matter if
		# they are online or not. This will be one line per node like
		# rabbit@overcloud-rabbit-0
		# rabbit@overcloud-rabbit-1
		# ...
		local remote_join_list=$(cibadmin -Q --xpath "//node_state//nvpair[@name='$RMQ_CRM_ATTR_COOKIE']" | grep "$RMQ_CRM_ATTR_COOKIE" | sed -n -e "s/^.*value=.\(.*\)\".*$/\1/p")
		# The following expression prepares a filter like '-e overcloud-rabbit-0 -e overcloud-rabbit-1 -e ...'
		local filter=$(crm_mon -r --as-xml | xmllint --format --xpath "//nodes//node[@online='true' and @standby='false']/@name" - | xargs -n1 echo | awk -F= '{print "-e "$2}')
		# export the intersection which gives us only the nodes that
		# a) wrote their namein the cib attrd
		# b) run on nodes where pacemaker_remote is enabled
		join_list="$(echo $remote_join_list | grep $filter)"
	fi

	echo $join_list
}

rmq_write_nodename()
{
	local node_name=$(rmq_local_node)

	if [ -z "$node_name" ]; then
		ocf_log err "Failed to determine rabbitmq node name, exiting"
		exit $OCF_ERR_GENERIC
	fi

	# store the pcmknode to rmq node mapping as a transient attribute. This allows
	# us to retrieve the join list with a simple xpath.
	${HA_SBIN_DIR}/crm_attribute -N $NODENAME -l reboot --name "$RMQ_CRM_ATTR_COOKIE" -v "$node_name"

	# the pcmknode to rmq node mapping as a permanent attribute as well. this lets
	# us continue to map offline nodes to their equivalent rmq node name
	${HA_SBIN_DIR}/crm_attribute -N $NODENAME -l forever --name "$RMQ_CRM_ATTR_COOKIE_LAST_KNOWN" -v "$node_name"
}

rmq_delete_nodename()
{
	# remove node-name
	${HA_SBIN_DIR}/crm_attribute -N $NODENAME -l reboot --name "$RMQ_CRM_ATTR_COOKIE" -D
}

prepare_dir () {
	if [ ! -d ${1} ] ; then
		mkdir -p ${1}
		chown -R rabbitmq:rabbitmq ${1}
		chmod 755 ${1}
	fi
}

remove_pid () {
	rm -f ${RMQ_PID_FILE} > /dev/null 2>&1
}

rmq_app_running() {
	if $RMQ_EVAL 'application:which_applications().' | grep -q '{rabbit,'; then
		ocf_log debug "RabbitMQ application is running"
		return $OCF_SUCCESS
	else
		ocf_log debug "RabbitMQ application is stopped"
		rmq_delete_nodename
		return $OCF_NOT_RUNNING
	fi
}

rmq_node_alive() {
	if $RMQ_EVAL 'ok.'; then
		ocf_log debug "RabbitMQ node is alive"
		return $OCF_SUCCESS
	else
		ocf_log debug "RabbitMQ node is down"
		rmq_delete_nodename
		return $OCF_NOT_RUNNING
	fi
}

rmq_monitor() {
	local rc

	status=$($RMQ_EVAL 'rabbit_mnesia:cluster_status_from_mnesia().' 2>&1)
	if echo "${status}" | grep -q '^{ok'; then
		pcs_running=$(rmq_join_list | wc -w)
		ocf_log debug "Pacemaker thinks ${pcs_running} RabbitMQ nodes are running"
		rmq_running=$($RMQ_EVAL 'length(mnesia:system_info(running_db_nodes)).')
		ocf_log debug "RabbitMQ thinks ${rmq_running} RabbitMQ nodes are running"

		if [ $(( $rmq_running * 2 )) -lt $pcs_running ]; then
			ocf_log info "RabbitMQ is a minority partition, failing monitor"
			rmq_delete_nodename
			return $OCF_ERR_GENERIC
		fi

		ocf_log debug "RabbitMQ server is running normally"
		rmq_write_nodename

		return $OCF_SUCCESS
	else
		ocf_log info "RabbitMQ server could not get cluster status from mnesia"
		ocf_log debug "${status}"
		rmq_delete_nodename
		return $OCF_NOT_RUNNING
	fi
}

rmq_init_and_wait()
{
	local rc

	prepare_dir $RMQ_PID_DIR
	prepare_dir $RMQ_LOG_DIR
	remove_pid

	# the server startup script uses this environment variable
	export RABBITMQ_PID_FILE="$RMQ_PID_FILE"

	setsid sh -c "$RMQ_SERVER > ${RMQ_LOG_DIR}/startup_log 2> ${RMQ_LOG_DIR}/startup_err" &

	ocf_log info "Waiting for server to start"
	$RMQ_CTL wait $RMQ_PID_FILE
	rc=$?
	if [ $rc -ne $OCF_SUCCESS ]; then
		remove_pid
		ocf_log info "rabbitmq-server start failed: $rc"
		return $OCF_ERR_GENERIC
	fi

	rmq_app_running
	return $?
}

rmq_set_policy()
{
	$RMQ_CTL set_policy "$@" > /dev/null 2>&1
}

rmq_start_first()
{
	local rc

	ocf_log info "Bootstrapping rabbitmq cluster"
	rmq_wipe_data
	rmq_init_and_wait
	rc=$?

	if [ $rc -eq 0 ]; then
		rc=$OCF_SUCCESS
		ocf_log info "cluster bootstrapped"
		rmq_write_nodename

		if [ -n "$OCF_RESKEY_set_policy" ]; then
			# do not quote set_policy, we are passing in arguments
			rmq_set_policy $OCF_RESKEY_set_policy
			if [ $? -ne 0 ]; then
				ocf_log err "Failed to set policy: $OCF_RESKEY_set_policy"
				rc=$OCF_ERR_GENERIC
			else 
				ocf_log info "Policy set: $OCF_RESKEY_set_policy"
			fi
		fi

	else
		ocf_log info "failed to bootstrap cluster. Check SELINUX policy"
		rc=$OCF_ERR_GENERIC
	fi

	return $rc
}

rmq_is_clustered()
{
    $RMQ_EVAL 'rabbit_mnesia:is_clustered().' | grep -q true
}

rmq_join_existing()
{
	local join_list="$1"
	local rc=$OCF_ERR_GENERIC

	ocf_log info "Joining existing cluster with [ $(echo $join_list | tr '\n' ' ') ] nodes."
	rmq_init_and_wait
	if [ $? -ne 0 ]; then
		return $OCF_ERR_GENERIC
	fi

        if rmq_is_clustered; then
            ocf_log info "Successfully re-joined existing rabbitmq cluster automatically"
            return $OCF_SUCCESS
        fi

	# unconditionally join the cluster
	$RMQ_CTL stop_app > /dev/null 2>&1
	for node in $(echo "$join_list"); do
		ocf_log info "Attempting to join cluster with target node $node"
		$RMQ_CTL join_cluster $node
		if [ $? -eq 0 ]; then
			ocf_log info "Joined cluster by connecting to node $node, starting app"
			$RMQ_CTL start_app
			rc=$?
			if [ $rc -ne 0 ]; then
				ocf_log err "'$RMQ_CTL start_app' failed"
			fi
			break;
		fi
	done

	if [ "$rc" -ne 0 ]; then
		ocf_log info "Join process incomplete, shutting down."
		return $OCF_ERR_GENERIC
	fi

	ocf_log info "Successfully joined existing rabbitmq cluster"
	return $OCF_SUCCESS
}

rmq_forget_cluster_node_remotely() {
	local running_cluster_nodes="$1"
	local node_to_forget="$2"

	ocf_log info "Forgetting $node_to_forget via nodes [ $(echo $running_cluster_nodes | tr '\n' ' ') ]."
	for running_cluster_node in $running_cluster_nodes; do
		$RMQ_CTL -n $running_cluster_node forget_cluster_node $node_to_forget
		if [ $? = 0 ]; then
			ocf_log info "Succeeded forgetting $node_to_forget via $running_cluster_node."
			return
		else
			ocf_log err "Failed to forget node $node_to_forget via $running_cluster_node."
		fi
	done
}

rmq_notify() {
	node_list="${OCF_RESKEY_CRM_meta_notify_stop_uname}"
	mode="${OCF_RESKEY_CRM_meta_notify_type}-${OCF_RESKEY_CRM_meta_notify_operation}"


	# When notifications are on, this agent is going to "forget" nodes once they
	# leave the cluster. This is thought to resolve some issues where rabbitmq
	# blocks trying to sync with an offline node after a fencing action occurs.
	if ! [ "${mode}" = "post-stop" ]; then
		return $OCF_SUCCESS
	fi

	rmq_monitor
	if [ $? -ne $OCF_SUCCESS ]; then
		# only run forget when we are for sure active 
		return $OCF_SUCCESS
	fi

	# forget each stopped rmq instance in the provided pcmk node in the list.
	for node in $(echo "$node_list"); do
		local rmq_node="$(${HA_SBIN_DIR}/crm_attribute -N $(ocf_attribute_target $node) -l forever --query --name $RMQ_CRM_ATTR_COOKIE_LAST_KNOWN -q)"
		if [ -z "$rmq_node" ]; then
			ocf_log warn "Unable to map pcmk node $node to a known rmq node."
			continue	
		fi
		ocf_log notice "Forgetting stopped node $rmq_node"
		$RMQ_CTL forget_cluster_node $rmq_node
		if [ $? -ne 0 ]; then
			ocf_log warn "Unable to forget offline node $rmq_node."
		fi
	done
	return $OCF_SUCCESS
}

rmq_try_start() {
	local join_list=""
	local rc

	rmq_monitor
	if [ $? -eq $OCF_SUCCESS ]; then
		return $OCF_SUCCESS
	fi

	join_list=$(rmq_join_list)

	# No join list means no active instances are up. This instance
	# is the first, so it needs to bootstrap the rest
	if [ -z "$join_list" ]; then
		rmq_start_first
		rc=$?
		return $rc
	fi

	# Try to join existing cluster
	ocf_log info "wiping data directory before joining"
	local local_rmq_node="$(${HA_SBIN_DIR}/crm_attribute -N $NODENAME -l forever --query --name $RMQ_CRM_ATTR_COOKIE_LAST_KNOWN -q)"

	rmq_stop
	rmq_wipe_data
	rmq_forget_cluster_node_remotely "$join_list" "$local_rmq_node"
	rmq_join_existing "$join_list"
	rc=$?

	if [ $rc -ne 0 ]; then
		# we could not join the rabbitmq cluster from any of the running nodes
		# this might be due to a unexpected reset of those nodes. Give ourself
		# a chance to start by retrying the entire start sequence.

		ocf_log warn "Failed to join the RabbitMQ cluster from nodes ${join_list}. Stopping local unclustered rabbitmq"
		rmq_stop

		ocf_log warn "Re-detect available rabbitmq nodes and try to start again"
		# return an unused OCF value to signify a "retry" condition
		return $RMQ_TRY_RESTART_ERROR_CODE
	fi

	# Restore users, user permissions, and policies (if any)
	BaseDataDir=`dirname $RMQ_DATA_DIR`
	$RMQ_EVAL "
		%% Run only if Mnesia is ready.
		lists:any(fun({mnesia,_,_}) -> true; ({_,_,_}) -> false end, application:which_applications()) andalso
		begin
			Restore = fun(Table, PostprocessFun, Filename) ->
				case file:consult(Filename) of
					{error, _} ->
						ok;
					{ok, [Result]} ->
						lists:foreach(fun(X) -> mnesia:dirty_write(Table, PostprocessFun(X)) end, Result),
						file:delete(Filename)
				end
			end,

			%% Restore users

			Upgrade = fun
				({internal_user, A, B, C}) -> {internal_user, A, B, C, rabbit_password_hashing_md5};
				({internal_user, A, B, C, D}) -> {internal_user, A, B, C, D}
			end,

			Downgrade = fun
				({internal_user, A, B, C}) -> {internal_user, A, B, C};
				({internal_user, A, B, C, rabbit_password_hashing_md5}) -> {internal_user, A, B, C};
				%% Incompatible scheme, so we will loose user's password ('B' value) during conversion.
				%% Unfortunately, this case will require manual intervention - user have to run:
				%%    rabbitmqctl change_password <A> <somenewpassword>
				({internal_user, A, B, C, _}) -> {internal_user, A, B, C}
			end,

			%% Check db scheme first
			[WildPattern] = ets:select(mnesia_gvar, [ { {{rabbit_user, wild_pattern}, '\\\$1'}, [], ['\\\$1'] } ]),
			case WildPattern of
				%% Version < 3.6.0
				{internal_user,'_','_','_'} ->
					Restore(rabbit_user, Downgrade, \"$BaseDataDir/users.erl\");
				%% Version >= 3.6.0
				{internal_user,'_','_','_','_'} ->
					Restore(rabbit_user, Upgrade, \"$BaseDataDir/users.erl\")
			end,

			NoOp = fun(X) -> X end,

			%% Restore user permissions
			Restore(rabbit_user_permission, NoOp, \"$BaseDataDir/users_perms.erl\"),

			%% Restore policies
			Restore(rabbit_runtime_parameters, NoOp, \"$BaseDataDir/policies.erl\")
		end.
	"
	return $OCF_SUCCESS
}

rmq_start() {
	local rc=$RMQ_TRY_RESTART_ERROR_CODE
	while [ $rc -eq $RMQ_TRY_RESTART_ERROR_CODE ]; do
		rmq_try_start
		rc=$?
	done
	return $rc
}

rmq_stop() {
	# Backup users, user permissions, and policies
	BaseDataDir=`dirname $RMQ_DATA_DIR`
	$RMQ_EVAL "
		%% Run only if Mnesia is still available.
		lists:any(fun({mnesia,_,_}) -> true; ({_,_,_}) -> false end, application:which_applications()) andalso
		begin
			Backup = fun(Table, SelectPattern, Filter, Filename) ->
				Result = case catch mnesia:dirty_select(Table, [{SelectPattern, [Filter], ['\\\$_']}]) of
					{'EXIT', _} -> [];
					Any -> Any
				end,
				Result /= [] andalso file:write_file(Filename, io_lib:fwrite(\"~p.~n\", [Result]))
			end,

			%% Backup users
			%% Check db scheme first
			[WildPattern] = ets:select(mnesia_gvar, [ { {{rabbit_user, wild_pattern}, '\\\$1'}, [], ['\\\$1'] } ]),
			UsersSelectPattern = case WildPattern of
				%% Version < 3.6.0
				{internal_user,'_','_','_'} -> {internal_user, '\\\$1', '_', '_'};
				%% Version >= 3.6.0
				{internal_user,'_','_','_','_'} -> {internal_user, '\\\$1', '_', '_', '_'}
			end,
			Backup(rabbit_user, UsersSelectPattern, {'/=', '\\\$1', <<\"guest\">>}, \"$BaseDataDir/users.erl\"),

			%% Backup user permissions
			Backup(rabbit_user_permission, {'\\\$1', {'\\\$2', '\\\$3','\\\$4'}, '\\\$5'}, {'/=', '\\\$3', <<\"guest\">>}, \"$BaseDataDir/users_perms.erl\"),

			%% Backup policies
			Backup(rabbit_runtime_parameters, {runtime_parameters, {'_', '\\\$1', '_'}, '_'}, {'==', '\\\$1', <<\"policy\">>}, \"$BaseDataDir/policies.erl\")
		end.
	"

	rmq_node_alive
	if [ $? -eq $OCF_NOT_RUNNING ]; then
		return $OCF_SUCCESS
	fi

	$RMQ_CTL stop
	rc=$?

	if [ $rc -ne 0 ]; then
		ocf_log err "rabbitmq-server stop command failed: $RMQ_CTL stop, $rc"
		return $rc
	fi

	#TODO add kill logic
	stop_wait=1
	while [ $stop_wait = 1 ]; do
		rmq_app_running
		rc=$?
		if [ "$rc" -eq $OCF_NOT_RUNNING ]; then
			stop_wait=0
			break
		elif [ "$rc" -ne $OCF_SUCCESS ]; then
			ocf_log info "rabbitmq-server stop failed: $rc"
			exit $OCF_ERR_GENERIC
		fi
		sleep 1
	done

	rmq_delete_nodename
	remove_pid
	return $OCF_SUCCESS
}

rmq_validate() {
	check_binary $RMQ_SERVER
	check_binary $RMQ_CTL

	# This resource only makes sense as a clone right now. at some point
	# we may want to verify the following.
	#TODO verify cloned
	#TODO verify ordered=true

	# Given that this resource does the cluster join explicitly,
	# having a cluster_nodes list in the static config file will
	# likely conflict with this agent. 
	#TODO verify no cluster list in rabbitmq conf
	#cat /etc/rabbitmq/rabbitmq.config | grep "cluster_nodes"

	return $OCF_SUCCESS
}

case $__OCF_ACTION in
meta-data)	meta_data
		exit $OCF_SUCCESS
		;;
start)		rmq_start;;
stop)		rmq_stop;;
monitor)	rmq_monitor;;
validate-all)	rmq_validate;;
notify)		rmq_notify;;
usage|help)	rmq_usage
		exit $OCF_SUCCESS
		;;
*)		rmq_usage
		exit $OCF_ERR_UNIMPLEMENTED
		;;
esac
rc=$?
ocf_log debug "${OCF_RESOURCE_INSTANCE} $__OCF_ACTION : $rc"
exit $rc

